This D250X effect pedal is based on 250 Preamp .2 functional knobs: Gain and Level controls; Two Models (D/M) to choose.ON/ OFF LED indicator light.True bypass allows your guitar tone to remain pristine even when the D250X is off.Full metal shell and compact size, durable and portable.Function knobs:Gain: Controls the amount of distortion, from just a Press of grit to all-out grind.Level: Dials in some body for "always on" performance or huge amounts of boost for boosting solos above a dense stage mix.With the Gain all the way down, crank up the Level to boost your sound and cut through during your solos.Specifications:Input: 1/4 inch monaural Output: 1/4 inch monaural Power : 9VDC, Negative Tips (Regulated recommended)Colour:OrangeMaterial:metalSize:9.2 * 3.8 * 3.6cmPackage Contents:1 * Effect PedalOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.